The nucleosome is the structural repeat unit within the chromosomal material of all eukaryotic cells. This unit is not homogeneous, nor is it likely to be conformationally static. Accumulated evidence suggests regions of the eukaryotic genome that have the potential to be transcribed or are being actively transcribed, maintain inter- or intra-nucleosomal structures significantly different from those regions of the genome permanently transcriptionally silent. It is the purpose of the investigation to determine the nature of the nucleosomal proteins within the transcriptionally active regions of the genome, as well as the functional significance of histone acetylation. Further, a significant portion of the research will be to ascertain the conformational role of histone acetylation. Physical biochemical methods will be used to determine whether isolated nucleosomes containing hyperacetylated histones display physical properties different from normal nucleosomes. It is postulated that interactions between and within nucleosomes will be weakened. Information from this investigation will yield a deeper understanding of the mechanisms modulating chromatin structure and help determine the importance of these mechanisms in controlling eukaryotic gene expression.